The pit bull bit Shields' dog and bit the owner when he tried to pull the canines apart, police said. When he couldn't separate the animals, Shields went back into his home and grabbed a large kitchen knife.

Shields repeatedly stabbed the pit bull when he was unsuccessful separating the dogs for a second time, police said. The pit bull died at the scene.

Shields was taken to a hospital in the area for his injuries and his dog was taken to a veterinarian for medical treatment. Both had non-life-threatening injuries.

Officers soon found the pit bull's owner, Jeremy Scott, and he was cited for a dangerous dog municipal code violation, police said. He faces a fine up to $500 in Sherwood Municipal Court, according to police.

Police have not released any details on how the pit bull got loose in the area.

When reached by The Oregonian Tuesday, a man who identified himself as Shields' son said the injured dog and its owner are recovering. The family declines commenting about the incident, he said.

When approached by an aggressive dog, Sherwood police suggest staying calm, remaining still and commanding the dog to go away.

"If the dog begins to bite you, fight back and protect your face, chest and throat," according to a statement on the police department's Facebook page. "Do what is needed to protect yourself."